Gas turbines include a rotor and rotating disks that are attached to the rotor, and airfoils that are positioned at the outer diameter of the disks. These components are surrounded by a turbine casing. Typically, a turbine casing is made in two segments, an upper turbine casing segment and a lower turbine casing segment, split on a horizontal centerline to facilitate assembly and provide access to the rotor and internal stationary portions of the turbine. The segments are normally connected through a bolted flange at their horizontal joint and act to contain the working fluid while maintaining the working fluid in intimate contact with the blade elements. The upper turbine casing segment may be installed between a compressor discharge casing (CDC) and exhaust casing vertical joints during gas turbine maintenance. The fit for the casing is tight and the structure is hung as it is installed. There are occasions, including in the manufacturing phase and during maintenance when the upper casing segment will require lifting. To facilitate lifting, the upper casing segment is fitted with lifting lugs to allow the component to be raised and moved.
The level continuous installation of the upper casing segment is a difficult task. The installation is usually carried out without specialized tools and generally requires significant manpower. The improper installation of the upper casing segment may cause quality issues such as galling and damage to the flange, distortion to the casing and bolting, as well as improper crane loading.